Combination sealing member and pipe couplings

ABSTRACT

A sealing member is disclosed having an outer surface that supports segments of a pipe coupling for joining pipe elements in end to end relation. The segments are supported in spaced relation to permit the pipe elements to be inserted into the coupling without disassembly. The sealing member is a flexible ring that has conical lips around its inner circumference to engage and guide the pipe elements into the coupling. A tongue extends radially inwardly between the lips, the tongue having conical shoulders which engage and guide the pipe ends. The tongue locates the coupling segments relatively to the pipe elements.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.11/128,728, filed May 13, 2005, which claims priority to U.S.Provisional Application No. 60/571,596, filed May 14, 2004.

FIELD OF THE INVENTION

This invention relates to flexible seals for use in combination withmechanical pipe couplings to ensure a fluid-tight joint.

BACKGROUND OF THE INVENTION

Mechanical couplings for joining pipe elements together end-to-endcomprise interconnectable segments that are positionablecircumferentially surrounding the end portions of co-axially alignedpipe elements. The term pipe element” is used herein to describe anypipe-like item or component having a pipe like form. Pipe elementsinclude pipe stock, pipe fittings such as elbows, caps and tees as wellas fluid control components such as valves, reducers, strainers,restrictors, pressure regulators and the like.

Each mechanical coupling segment comprises a housing having arcuatesurfaces which project radially inwardly from the housing and engageplain end pipe elements or circumferential grooves that extend aroundeach of the pipe elements to be joined. Engagement between the arcuatesurfaces and the pipe elements provides mechanical restraint to thejoint and ensures that the pipe elements remain coupled even under highinternal pressure and/or external forces. The housings define an annularchannel that receives a sealing member, typically an elastomeric ringwhich engages the ends of each pipe element and cooperates with thesegments to provide a fluid tight seal. The segments have connectionmembers, typically in the form of lugs which project outwardly from thehousings. The lugs are adapted to receive fasteners, such as nuts andbolts, which are adjustably tightenable to draw the segments toward oneanother.

To ensure a good fit between the couplings and the pipe elements, thearcuate surfaces on prior art couplings have a radius of curvature thatis substantially matched to the radius of curvature of the outer surfaceof the pipe element that it is intended to engage. For couplings usedwith grooved pipe elements, the radii of curvature of the arcuatesurfaces are smaller than the radii of curvature of the outer surfacesof the pipe elements outside of the grooves so that the arcuate surfacesfit within and engage the grooves properly.

This geometrical relation between the arcuate surfaces of the couplingsand the outer surfaces of the pipe elements in prior art couplingsresults in a tedious and time consuming installation process whenmechanical couplings are used. Typically, the coupling is received bythe technician with the segments bolted together and the ring sealcaptured within the segments' channels. The technician firstdisassembles the coupling by unbolting it, removes the ring seal,lubricates it (if not pre-lubricated) and places it around the ends ofthe pipe elements to be joined. Installation of the ring seal requiresthat it be lubricated and stretched to accommodate the pipe elements, anoften difficult and messy task, as the ring seal is usually stiff andthe lubrication makes manual manipulation of the seal difficult. Withthe ring seal in place on both pipe elements, the segments are thenplaced one at a time straddling the ends of the pipe elements andcapturing the ring seal against them. During placement, the segmentsengage the seal, the arcuate surfaces are aligned with the grooves, thebolts are inserted through the lugs, the nuts are threaded onto thebolts and tightened, drawing the coupling segments toward one another,compressing the seal and engaging the arcuate surface within thegrooves.

As evident from the previous description, installation of mechanicalpipe couplings according to the prior art requires that the techniciantypically handle at least seven individual piece parts (and more whenthe coupling has more than two segments), and must totally disassembleand reassemble the coupling. Significant time, effort and expense wouldbe saved if the technician could install a mechanical pipe couplingwithout first totally disassembling it and then reassembling it, pieceby piece.

SUMMARY OF THE INVENTION

The invention concerns, in combination, a coupling and a sealing member.The coupling comprises a plurality of segments joined end to end. Thecoupling secures pipe elements together in end to end relationship. Thesegments have arcuate surfaces facing inwardly which are engageable withouter surfaces of the pipe elements. The segments also have adjustablytightenable connection members for drawing them together. The sealingmember is positioned between the segments and comprises a flexible,resilient ring having a ring inner surface adapted to engage the outersurfaces of the pipe elements. The ring inner surface has a diametersized to receive the pipe elements upon insertion of the pipe elementsbetween the segments. The ring has a ring outer surface with a diametersized to support the segments in spaced apart relation sufficient toallow the pipe elements to be inserted therebetween. Tightening of theconnection members move the segments toward one another, compressing thering. The ring is deformable upon motion of the segments to permitengagement of the arcuate surfaces with the pipe elements.

Preferably, the ring inner surface comprises first and second lipsextending circumferentially around the ring. The lips are positioned onopposite sides of the ring in spaced apart relation and projectsubstantially inwardly toward one another. The lips are adapted toengage the outer surfaces of the pipe elements and form a fluid tightseal when the ring is compressed by the segments.

The first and second lips each have a conical surface facing outwardlyfrom the ring. The conical surfaces have a width sized to engage andguide the pipe elements between the segments when the pipe elements areinserted therebetween.

The sealing member may also have a backwall that forms the ring outersurface. First and second sidewalls are positioned in spaced apartrelation on opposite sides of the ring. The sidewalls extendsubstantially radially inwardly from the backwall. The first lip isattached to the first sidewall, and the second lip is attached to thesecond sidewall. A tongue is attached to the backwall and extendscircumferentially around the ring. The tongue is positioned between thefirst and the second lips and projects substantially radially inwardly.The tongue engages ends of the pipe elements upon insertion thereofbetween the segments. The tongue facilitates positioning the segmentsrelatively to the pipe elements.

Preferably, the tongue comprises a root portion attached to thebackwall, and a tip portion extending from the root portion. The tipportion has a smaller thickness than the root portion, and a pair ofshoulders are formed on opposite sides of the tongue between the rootportion and the tip portion. Each of the shoulders has a conical profileshape for engaging and guiding the pipe elements upon insertion thereofbetween the segments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view, partially cut away, of an embodiment of asealing member according to the invention;

FIG. 2 is a perspective view, partially cut away, of another embodimentof a sealing member according to the invention;

FIG. 2A is a perspective view, partially cut away, of another embodimentof a sealing member according to the invention;

FIG. 2B is a perspective view, partially cut away, of yet anotherembodiment of a sealing member according to the invention;

FIG. 3 is a cross sectional view of a sealing member embodimentaccording to the invention;

FIG. 4 is an axial cross sectional view of a coupling using a sealingmember according to the invention;

FIGS. 5 and 6 are longitudinal sectional views of the coupling shown inFIG. 4;

FIG. 7 is an axial cross sectional view of the coupling shown in FIG. 4;

FIGS. 8 and 9 are longitudinal sectional views of pipe joints usingsealing members according to the invention;

FIGS. 10 and 11 are axial views of pipe coupling embodiments that usethe sealing member according to the invention; and

FIG. 12 is a longitudinal sectional view of an embodiment of a sealingmember according to the invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 shows a perspective view of a sealing member 10 according to theinvention. Sealing member 10 comprises a flexible, resilient ring 12having a ring inner surface 14. Preferably, ring inner surface 14 isformed of a pair of lips 16 and 18 that are attached to respectivesidewalls 20 and 22 that extend from a backwall 24. Backwall 24 providesa ring outer surface 26 that extends circumferentially around the ring.The sidewalls and the lips are positioned in spaced apart relation onopposite sides of the ring 12. Lips 16 and 18 project substantiallyinwardly toward one another and have respective conical surfaces 28 and30 that slope inwardly toward the center of ring 12 to act as a lead-into guide pipe elements into engagement with the sealing member asdescribed below.

In a preferred embodiment 32 of the sealing member, shown in FIG. 2,ring 12 further includes a tongue 34. Tongue 34 is positioned betweenlips 16 and 18 and has a root portion 36 that is attached to thebackwall 24 opposite to the ring outer surface 26. Tongue 34 projectssubstantially radially inwardly from the backwall 24 and extendscircumferentially around ring 12. The tongue may be substantiallycontinuous, as shown in FIG. 2, or may comprise a plurality of sections34 a in spaced apart relation to one another around the ring as shown inFIG. 2A. In another embodiment, shown in FIG. 2B, the root portion 36 oftongue 34 is not attached to the backwall 24, but has a flared base 36 athat engages the backwall and side walls 20 and 22 to maintain thetongue in position between lips 16 and 18.

In a preferred embodiment 32, best shown in FIG. 3, tongue 34 has a tipportion 38 extending from the root portion 36. The thickness 40 of tipportion 38 is smaller than the thickness 42 of the root portion 36. Thisdimensional relation results in a pair of shoulders 44 and 46 beingformed between the root and tip portions. Preferably, the shoulders 44and 46 have conical profile shapes for engaging and guiding pipeelements as described below. Cone angles 48 up to about 30° areadvantageous for the functioning of the tongue 34.

As shown in FIG. 4, sealing members such as 10 and 32 are used withmechanical couplings 50 for securing pipe elements together in end toend relation, the sealing members ensuring a fluid tight joint.(Hereinafter, sealing member embodiment 32 is described, it beingunderstood that the description applies to all sealing memberembodiments according to the invention.)

Coupling 50 comprises a plurality of coupling segments, in this example,two segments 52 and 54. The coupling segments are connected to oneanother by adjustably tightenable connection members 56, whichpreferably comprise lugs 58 that extend outwardly from the ends of eachsegment and are positioned in facing relation to one another to receivefasteners 60, such as bolts 62 and nuts 64. Each segment also has a pairof arcuate surfaces 66 that are positioned in spaced relation to oneanother and face inwardly for engagement with the outer surfaces ofrespective pipe elements as described below.

FIG. 4 further shows the coupling 50 in a preassembled state, withsegments 52 and 54 supported on the ring outer surface 26, the segmentsbeing held together in the preassembled state by the fasteners 60. Thecoupling 50 is preassembled under controlled conditions at themanufacturing facility and arrives on site in the preassembled state,ready for immediate use. As shown in FIG. 5, sealing member 32 isdesigned so that the ring outer surface 26 has a diameter 68 sized tomaintain the segments 52 and 54 in spaced relation with sufficientclearance to allow pipe elements 70 and 72 to be inserted between thesegments 52 and 54 without disassembling the coupling. Use of sealsaccording to the invention thus provides significant advantage inreducing the labor required for assembly of the pipe joint as thecoupling does not require total or even partial disassembly prior to theinstallation. Sealing member 32 also has sufficient stiffness tomaintain the coupling segments in spaced apart relation through shippingand handling during installation, but is resilient and flexible,allowing it to deform as required when the fasteners 60 are tightened todraw the coupling segments 52 and 54 toward one another and engage thecoupling arcuate surfaces 66 with the pipe elements as shown in FIGS. 6and 7 to secure the pipe elements 70 and 72 in end to end relation andprovide a fluid tight joint.

Note that the conical surfaces 28 and 30 of lips 16 and 18 each have awidth 74 (see FIG. 3) that is sized so that the pipe elements engage thelips on the conical surfaces as they are inserted into coupling 50 (seeFIG. 5). This conical lip geometry facilitates assembly of the pipejoint with the preassembled coupling. The lips serve as a lead in toguide the pipe elements into proper engagement with the seal, and alsoeliminate the need to remove the seal from the coupling and manuallystretch and deform it to enable it to receive the pipe elements, as mustbe done for prior art seals.

Tongue 34 also enhances the ability to quickly and conveniently installpipe elements into the preassembled coupling 50. The conical profile ofshoulders 44 and 46 further serve as a lead-in to guide the pipeelements into proper engagement with the sealing member 32. Theshoulders 44 and 46 engage the ends of the pipe elements and limit thetongue's extension into the bore of the pipe elements where it mightimpede fluid flow and increase the head loss. Head loss due toresistance in joints becomes significant for long pipe runs having manyjoints, and is to be avoided. The tongue itself further serves as a stopto align the arcuate surfaces 66 of segments 52 and 54 with a desiredtarget on the outer surface of the pipe elements, in the example shownin FIGS. 5 and 6, circumferential grooves 74 and 76. Engagement betweenthe grooves and the arcuate surfaces provide mechanical restraint tosecure the pipe elements to the coupling.

Virtually any type of pipe element will benefit from the use of sealsaccording to the invention. If plain end pipe elements are used (notshown), the target may be witness marks formed on the outer surface toindicate proper engagement depth between pipe element and coupling. Asshown in FIGS. 8 and 9, pipe elements having shoulders 78 (FIG. 8) orpipe elements having flared ends 80 (FIG. 9) may be used with thesealing member according to the invention, the sealing member beingreadily geometrically adaptable to receive the various types of pipeelements.

Sealing members according to the invention may also be used with anytype of multi-segment coupling where a seal is used to maintainseparation between the segments in a preassembled state. The couplingsthemselves may have enhancements that provide additional clearance forinsertion of the pipe elements, allowing the segments to be closer toone another in the preassembled state and still permit direct insertionof the pipe elements without any disassembly. To this end, the couplingshown in FIG. 4 is deformable as shown by a comparison of FIGS. 4 and 7.In the undeformed state, the arcuate surfaces 66 have a greater radiusof curvature than the pipe elements that they are joining, and thesurfaces 66 also subtend an arc of less than 180°. This geometryprovides clearance at the 3 o'clock and 9 o'clock positions on thecoupling (for a two segment coupling) allowing pipe element insertion.The coupling segments are deformed by tightening fasteners 60, whichdraw the segments 52 and 54 toward each other and force the arcuatesurfaces 66 to engage the pipe elements and conform to its radius ofcurvature.

FIG. 10 illustrates a pipe coupling 82 having segments 84 with cut-outs86 at opposite ends of the arcuate surfaces 66. The cut-outs provide thedesired clearance enhancement for the coupling. FIG. 11 shows a hingedcoupling 88 wherein a sealing member 32 is used to maintain the segments90 and 92 open to permit pipe element insertion. In FIG. 12 the sealingmember 94 has one sidewall 96 that is wider than its other sidewall 98.This geometry positions the lip 100 attached to sidewall 96 at a smallerdiameter than lip 102 attached to sidewall 98. The different diameterlips allow the seal to be used to couple pipe elements 104 and 106having different diameters.

Sealing members according to the invention used with multi-segmentcouplings provide a significant advantage in assembly of pipe jointsbecause they permit the couplings to be maintained in spaced relation ina preassembled state that facilitates assembly of the joint without theneed to first disassemble the couplings.

1. In combination, a sealing member and a coupling, said couplingcomprising: a plurality of segments joined end to end, said coupling forsecuring pipe elements together in end to end relationship, saidsegments having arcuate surfaces facing inwardly and engageable withouter surfaces of said pipe elements, said segments having adjustablytightenable connection members for drawing said segments together, saidsealing member being positioned between said segments and comprising: aflexible, resilient ring having a ring inner surface adapted to engagesaid outer surfaces of said pipe elements, said ring inner surfacehaving a diameter sized to receive said pipe elements upon insertion ofsaid pipe elements between said segments, said ring having a ring outersurface having a diameter sized to support said segments in spaced apartrelation sufficient to allow said pipe elements to be insertedtherebetween; and wherein upon tightening of said connection memberssaid segments being movable toward one another compressing said ring,said ring being deformable upon motion of said segments to permitengagement of said arcuate surfaces with said pipe elements.
 2. Acombination according to claim 1, wherein said ring inner surfacecomprises first and second lips extending circumferentially around saidring, said lips being positioned on opposite sides of said ring inspaced apart relation and projecting substantially inwardly toward oneanother, said lips being adapted to engage said outer surfaces of saidpipe elements and form a fluid tight seal when said ring is compressedby said segments.
 3. A combination according to claim 2, wherein saidfirst and second lips each have a conical surface facing outwardly fromsaid ring, said conical surfaces having a width sized to engage andguide said pipe elements between said segments when said pipe elementsare inserted therebetween.
 4. A combination according to claim 2,wherein said sealing member comprises: a backwall forming said ringouter surface; first and second sidewalls positioned in spaced apartrelation on opposite sides of said ring, said sidewalls extendingsubstantially radially inwardly from said backwall, said first lip beingattached to said first sidewall, said second lip being attached to saidsecond sidewall; and a tongue attached to said backwall and extendingcircumferentially around said ring, said tongue being positioned betweensaid first and said second lips and projecting substantially radiallyinwardly, said tongue engaging ends of said pipe elements upon insertionthereof between said segments, said tongue positioning said segmentsrelatively to said pipe elements.
 5. A combination according to claim 4,wherein said tongue comprises a root portion attached to said backwalland a tip portion extending from said root portion, said tip portionhaving a smaller thickness than said root portion, a shoulder beingformed between said root portion and said tip portion.
 6. A combinationaccording to claim 5, wherein said shoulder has a conical profile shapefor receiving and guiding said pipe elements upon insertion thereofbetween said segments.
 7. A combination according to claim 4, whereinsaid tongue comprises a root portion attached to said backwall and a tipportion extending from said root portion, said tip portion having asmaller thickness than said root portion, a pair of shoulders beingformed on opposite sides of said tongue between said root portion andsaid tip portion.
 8. A combination according to claim 7, wherein each ofsaid shoulders has a conical profile shape for engaging and guiding saidpipe elements upon insertion thereof between said segments.
 9. Acombination according to claim 8, wherein said conical profile of saidshoulders has a cone angle greater than 0° up to about 30°.
 10. Acombination according to claim 3, wherein said sealing member comprises:a backwall forming said ring outer surface; first and second sidewallspositioned in spaced apart relation on opposite sides of said ring, saidsidewalls extending substantially radially inwardly from said backwall,said first lip being attached to said first sidewall, said second lipbeing attached to said second sidewall; and a tongue attached to saidbackwall and extending circumferentially around said ring, said tonguebeing positioned between said first and said second lips and projectingsubstantially radially inwardly, said tongue engaging ends of said pipeelements upon insertion thereof between said segments, said tonguepositioning said segments relatively to said pipe elements.
 11. Acombination according to claim 10, wherein said tongue comprises a rootportion attached to said backwall and a tip portion extending from saidroot portion, said tip portion having a smaller thickness than said rootportion, a pair of shoulders being formed on opposite sides of saidtongue between said root portion and said tip portion.
 12. A combinationaccording to claim 11, wherein said shoulders have a conical profileshape for engaging and guiding said pipe elements upon insertion thereofbetween said segments.
 13. A combination according to claim 12, whereinsaid conical profile of said shoulders has a cone angle greater than 0°up to about 30°.
 14. A combination according to claim 4, wherein saidtongue extends substantially continuously around said ring.
 15. Incombination, a sealing ring and a coupling, said coupling comprising: aplurality of segments joined end to end, said coupling for securing pipeelements together in end to end relationship, said pipe elements havingan outer surface of substantially cylindrical profile, said segmentshaving arcuate surfaces facing inwardly and engageable with said pipeelement outer surfaces, said segments having adjustably tightentableconnection members for drawing said segments together, said sealing ringbeing positioned between said segments and comprising: a radially facingbackwall having a ring outer surface having a diameter sized to supportsaid segments in spaced apart relation sufficient to allow said pipeelements to be inserted therebetween; first and second sidewallsextending substantially radially inwardly from said backwall, saidsidewalls being in spaced apart relation on opposite sides of said ring;first and second lips attached respectively to said first and secondsidewalls, said lips projecting inwardly toward one another, and eachhaving a conical surface facing outwardly and adapted to engage andguide said pipe elements inserted between said segments; a tongueattached to said backwall and extending circumferentially around saidring, said tongue being positioned between said first and said secondlips and projecting substantially radially inwardly, said tongue beingengageable with said pipe elements upon insertion thereof forpositioning said segments relatively to said pipe elements; and whereinupon tightening of said connection members said segments being movabletoward one another compressing said ring, said ring being deformableupon motion of said segments to permit engagement of said arcuatesurfaces with said pipe elements.
 16. A combination according to claim15, wherein said tongue comprises a root portion attached to saidbackwall and a tip portion extending from said root portion, said tipportion having a smaller thickness than said root portion, a pair ofshoulders being formed on opposite sides of said tongue between saidroot portion and said tip portion.
 17. A combination according to claim16, wherein said shoulders have a conical profile shape for engaging andguiding said pipe elements upon insertion thereof between said segments.18. A combination according to claim 17, wherein said conical profile ofsaid shoulders has a cone angle greater than 0° up to about 30°.